To study the conversion of aromatic nitrogen-containing pollutants into toxic hydroxamic acids in marine organisms. The proposed biochemical pathway by which this process is expected to occur has been previosly elucidated by this investigator. This unique and abnormal biochemical conversion is based upon the reaction of aromatic nitroso compounds with cofactor intermediates of thiamine present in certain enzymes. These enzymes are universally distributed in living systems. Both in-vitro and in-vivo studies will be conducted with representative marine oraganisms, primarily invertebrates. The chemicals to be employed are representaties nitrogenous pollutants, one of which is a known carcinogen. Initial studies will involve the use of unlabelled chemicals, with later studies employing 14C radiolabelled compounds. This study will enable us to estimate the potential hazard of certain man-made pollutants both to the health of the marine environment and to human health. The potential human health problem is one of environmental carcinogenesis.